Short answer. Immediately. Section 21 requires the forensic laboratory examiner to issue a certification of the examination results immediately upon receipt of the seized items. The only exception is a volume too large to test in time, where a partial report may be issued first, with the final certification to follow once testing is done.
What the law says
A certification of the forensic laboratory examination results, which shall be done by the forensic laboratory examiner, shall be issued immediately upon the receipt of the subject item/s
RA 9165, Section 21 — Chain Of Custody. Read the full provision →
The word the statute uses is 'immediately'
Section 21 does not give the laboratory a comfortable window. It provides that a certification of the forensic laboratory examination results, which shall be done by the forensic laboratory examiner, shall be issued immediately upon the receipt of the subject item/s. Two things sit in that line. The certification is the examiner's own act — the person who did the testing, not an administrator. And the timing standard is immediacy on receipt, not a target measured in days or weeks. The design assumes the seized item is tested and certified promptly rather than sitting in a queue.
Why the speed is built into the chain of custody
The certification is the point where the seized substance is confirmed to be a dangerous drug at all, and where its examined quantity is fixed. Requiring it immediately narrows the interval during which the item sits in the laboratory before its identity and amount are recorded — the same concern that drives the inventory and photograph requirements earlier in the section. A prompt certification is easier to tie cleanly to the item that was received; a long, unexplained delay before certification is exactly the kind of gap a later review of the chain of custody will ask about.
The one exception, for bulk seizures
The immediacy rule bends only where the sheer volume makes it impossible. Section 21 allows that when the quantity does not permit testing to be completed in the time frame, a partial laboratory examination report may be provisionally issued, stating the quantities still to be examined. But that is a carve-out for large hauls, not a general licence to delay, and it comes with its own follow-through: a final certification must issue immediately upon completion of the examination. A partial report with no eventual final certification leaves the testing formally unfinished.
What to check in a specific file
If you are looking at how a seizure was handled, the certification's date against the date the laboratory received the item is a useful thing to compare, along with who signed it and whether a final certification followed any partial one. These are documents the defence and prosecution both work from, and they are best read together with the inventory and the request for laboratory examination. A lawyer reviewing the sequence can tell whether the statutory timing was met or whether an unexplained gap is worth pursuing.